Genetic diversity and antibiotic resistance profiles of Campylobacter jejuni isolates from poultry and humans in Turkey

• Human and poultry C. jejuni isolates were genotyped by PFGE and Rep PCR.
• The clonal proximity rates were detected between C. jejuni isolates.
• The discriminatory power of PFGE and Rep-PCR was similar.
• Chicken meat played an important role for infections caused by C. jejuni in Turkey.
• High rates of quinolone resistance were determined in C. jejuni isolates.

In this study, the investigation of clonal relations between human and poultry Campylobacter jejuni isolates and the determination of susceptibilities of isolates to various antibiotics were aimed. A total of 200 C. jejuni isolates concurrently obtained from 100 chicken carcasses and 100 humans were genotyped by the Pulsed-Field Gel Electrophoresis (PFGE) and automated Repetitive Extragenic Palindromic PCR (Rep-PCR, DiversiLab system) methods and were tested for their susceptibility to six antibiotics with disk diffusion method. The minimum inhibitory concentration (MIC) values of ciprofloxacin (CI), enrofloxacin (EF) and erythromycin (EM) were evaluated by E-test. By using PFGE 174 of (87.0%) the isolates were able to be typed. The clonally related strains were placed in 35 different clusters and 115 different genotypes were obtained. All of the two hundred isolates could be typed by using Rep-PCR and were divided into 133 different genotypes. One hundred and fourteen clonally related isolates (57.0%) were included in 47 clusters. In disk diffusion test, while the susceptibility rates of AMC and S to human and chicken derived C. jejuni isolates were 84.0%–96.0% and 96.0%–98.0%, respectively, all isolates were susceptible to gentamicin. The resistance rates of human isolates to AMP, NA and TE were detected as 44.0%, 84.0% and 38.0% of the resistances of chicken isolates to these antibiotics were 34.0%, 95.0% and 56.0%, respectively. The MIC values of human and chicken isolates to CI, EF and EM were detected as 81.0–93.0%, 85.0–88.0% and 6.0–7.0%, respectively. The clonal proximity rates were detected between human and poultry origin C. jejuni isolates. The discriminatory power of PFGE and Rep-PCR was similar, with Simpson's diversity indexes of 0.993 and 0.995, respectively. Concordance of the two methods as determined by Adjusted Rand coefficient was 0.198 which showed the low congruence between Rep-PCR and PFGE. High rates of quinolone resistance were detected in C. jejuni isolates.This study demonstrated that chicken meat played an important role for infections caused by C. jejuni in Turkey and erythromycin, amoxicillin clavulanic acid and gentamicin are recommended for the treatment of Campylobacteriosis in humans.